Preclinical and clinical fluorescence optical imaging instruments are increasingly utilized to obtain biological information on the path from gene to clinic (1). Skin and red blood cell autofluorescence occurs to some extent at all excitation wavelengths in visible wavelength range of light (400-700 nm). Due to this background signal, the quantification of fluorescence signals for in vivo imaging can be a difficult task when working in this range. To achieve better signal: background and increasingly accurate quantitative imaging in vivo, working within the near-infrared (NIR) wavelength range (700-900 nm) is desirable. In this spectral region, light absorption and scattering by physiologically abundant molecules such as hemoglobin, oxyhemoglobin, deoxyhemoglobin is minimized (2). NIR fluorescent contrast agents developed for in vivo optical imaging provide novel opportunities for pre-clinical diagnostic imaging in deep tissues (2). In this report we describe a novel, inexpensive near-infrared blood pool contrast agent and its utility in detecting capillary leak in animal models or muscle injury and cancer.